Knights and Knaves

My teacher brought up logic puzzles in math class. Knights always tell the truth, and knaves always lie. You have to figure out who’s lying.

I nodded as I scribbled down the wise words my professor told me. The bell gong’d, and I left my class. I exited the castle to go visit the village and test my new-found knowledge.

I found two people arguing, and I stepped in to intervene.

“Whoah there! Stop arguing, what’s going on here?” I shouted. The two of them began to unravel a story about stolen gold, armor, experience points, porcupines, and one of their mother’s.

“That’s… that’s just ludicrous!” I exclaimed indignantly. “I don’t understand what either of you are saying. Say it in a way I can understand! And by that, I mean say a single statement that can be either true, or false.”

The two of them stared to me.

There was a momentary silence, but one of them spoke. “I’m not lying! I swear!” he cried out.

I shook my head and held out my palm. “Calm down there good sir. That’s two statements, not one.”

The man cursed at me, then said in a stressed voice, “I. Am. Not. Lying.”

Okay, I understood that. I turned to the other guy.

This guy burst into a fit of rage, his face boiling red. “That guy right there is lying!”

I thought about that logic. Okay, I know that exactly one of them is lying…but…which one? I stood there frozen, I couldn’t figure it out.

I stared at the angry guy, waiting for some answer to pop into my head while he glared at me. Then I saw it. The ugly teeth, the dirty clothes, the hungry eyes. He was a poor knave. I looked at the other man, who was dressed in steel armor and held a bag of what I assumed to be gold coins, since that’s what they were arguing about.

I stalked up to the knave until I was right in his face, and stared him in the eye. “You sir, are a liar,” I said with confidence.

The man opened his mouth, then shut it. He clenched his fist and looked like he was about to explode like a watermelon filled with dynamite.

The knight, meanwhile, smiled and went on his merry way. With a bolt, the knave tackled the knight. “Stop! Thief!” the knave shouted.

That statement hit me like a fat guy punching me in the guts. Thief? What if everything I knew was wrong? What if he stole that armor? What if-